Process suitable for preparing homogeneous emulsions

ABSTRACT

Apparatus and process for preparing homogeneous emulsions incorporating the action of at least two centrifugal pumps with the driving force of two of the pumps tending to pull material in the opposite direction from the other.

[ 51 July 25, 1972 United States Patent Clocker [56] References Cited UNITED STATES PATENTS [541 PROCESS SUITABLE FOR PREPARING HOMOGENEOUS EMULSIONS Dron .....259/DIG. 30 2,734,728 2/1956 Myers..... .259/DIG 30 [72] Inventor: Edwin T. Clocker, St. Paul, Minn.

d u a r e 8 r e b l e .E Z 6 6 9 l 8 2 .l 8 6 3 Primary Examiner-Edward L. Roberts Assistant Examiner-Alan l. Cantor Attorney-Walter H. Schneider ABSTRACT Related (15. Application Data r nwm up mm ufl m w O mm? 8 bfin m omflm u g. men o w n 0 6 8 m w Pm .m wm m a e pe m m mfl P m M Mode n n m shwb m ettt .l. CC C C a e e 0 P 1 m 6 am fia elflBO Mann. lvf p am. 0 a @e 0.0 h vnrc A.mm.m 666 9 9 WH h 01.1 6 2m F 3 3 $8 9 0M7 3 I/ a 8 D 9 Il s 7 wm .0 3% N m MW 5 "5 u Ma S m f n m o m m 8 n H mm TL m om mmfl U 0 Mb mm& n L i C m d 0% 5mm CI.- UIF 1 1:11.. 3 2 8 6 555 .l [[r...

INVENTOR EDWIN T CLOCKER AT TOHNE Y PATENTESImzs 1912 I 3,579,1 2

sum 2 or 5 INVENTOR EDWIN T CLOCKER v JUL 2 m2 SHEEF 6F INVESTOR EDWIN T. CLQC E mmmmzs 1912 W a or 5 3.619; 1 82 FIGJI m T N E v m EDWIN T. CLOCKER PAYENTEMZ m2 3.679182 SHEET 5 BF 5 INVENTOR EDWIN T. CLOCKER PROCESS SUITABLE FOR PREPARING I-IOMOGENEOUS EMULSIONS RELATED CASES This application is a continuation-in-part of my copending application Ser. No. 798,393 filed Feb. 1 l, 1969, and now forfeit'ed.

BACKGROUND OF THE INVENTION My invention relates to a process for preparing homogeneous emulsions.

More particularly, my invention is concerned with a process for preparing emulsions incorporating the action of at least two centrifugal pumps with the driving force of two of the pumps tending to pull material in the opposite direction from each other.

In the continuous preparation of emulsions, numerous high shearing in-line blenders or emulsifiers have been used. The various mixers or blenders and processes, however, have a very high holdup capacity, and a high retention time. Also, these blenders are quite expensive as they are very specialized pieces of equipment, which require considerable know-how, time, and machining to prepare.

Continuing work is therefore being done in order to obtain in-line blenders and processes not processing the above deficlencies.

I have found that the novel process of my invention surprisingly and unexpectedly produce extremely good homogeneous emulsions, with low holdup and very low retention times. Furthermore, the apparatus of my invention is quite inexpensive and easy to assemble.

BRIEF DESCRIPTION OF INVENTION An apparatus comprises a housing; a first rotary impeller; at least one additional rotary impeller coaxial with the first rotary impeller; a barrier plate being located between said first and said additional rotary impellers, and having an orifice for permitting material to pass from one side of the plate to the other side of the plate; a shaft being supported in the housing; rigidly connecting the first and at least one additional impellers, and passing through the barrier plate(s); a material inlet located opposite the periphery of one of the impellers; and a material outlet located opposite the periphery of another impeller.

Another apparatus comprises a housing; a first rotary impeller; at least one additional rotary impeller coaxial with the first rotary impeller; a barrier means located between at least one set of adjacent rotary impellers, said barrier means having means for permitting material to pass from the periphery of said first rotary impeller to the periphery of an adjacent rotary impeller; a shaft being supported in said housing, rigidly connecting said first and said at least one additional impellers, and passing through said barrier means; a material inlet located at the hub of one of said impellers; and a material outlet located at the hub of another impeller.

In the drawings which accompany and form a part of this specification and disclosure and in which like numerals of reference denote corresponding parts throughout the several views:

FIG. 1 is a side elevation of a two section apparatus.

FIG. 2 is a section taken along line 2-2 in the direction of the arrows in FIG. 1.

FIG. 3 is a section taken along the 3-3 in the direction of the arrows in FIG. 2.

FIG. 4 is a view of the interior of the second or last casing.

FIG. 5 is a view of the interior of barrier plate 2.

FIG. 6 is a view of the interior of the first casing.

FIG. 7 is a side elevation of a three section apparatus.

FIG. 8 is a section taken along line 8-8 in the direction of the arrows in FIG. 7.

FIG. 9 is a view of the interior of the casing 41.

FIG. 10 is a section view of FIG. 8.

FIG. ll is a view of the interior of barrier plate 40.

FIG. 12 is a front view of a rotary impeller.

FIG. 13 is a sectional view of a two section apparatus.

FIG. 14 is a front view of rotary impeller 67.

The process of my invention comprises:

a. forcing at least two flowable materials through a first zone wherein a centrifugal force is present;

b. removing said materials from said first zone;

c. forcing said materials into at least one additional zone wherein another centrifugal force is present;

(I. the materials are forced through one of said zones against the radially outwardly directed centrifugal force therein and the materials are forced through the other zone in cooperation with the radially outwardly directed centrifugal force in the other zone; 7

e. the centrifugal forces in said first zone and said at least one additional zone tending to pull material in opposite directions; and

f. removing a homogeneous emulsion of the material from said at least one additional zone.

DESCRIPTION OF PREFERRED EMBODIMENT The apparatus which is shown in the drawings constitute preferred embodiments for performing the process of my invention. Referring to FIGS. 1-6, I have shown a housing which consists of a casing for a first section 1, a barrier plate 2, and a casing for a second section 3, all being connected together by fasteners 5 and 6 (e.g., nuts and bolts), a plug 4, a packing gland 12, a removable closure plate 9 being connected to the packing gland by fasteners 10 (e.g., bolts). The casing for the first section has a shaft opening 27, preferably in the middle.

The circular interior of the housing is divided into two sections by barrier plate 2 vertically positioned and having a diameter at least equal to the diameter of the interior of the housing. The barrier plate 2 has an orifice 25 which allows the material being emulsified to pass from one side to the other side of the plate. The mean cross-sectional area of the orifice 25 should be as small as possible to obtain greatest efficiency; but to avoid undue back-pressure, it is preferably at least equal in diameter to the inlet. It should be understood that the orifice may have a larger diameter equivalent to as much as half of the transverse cross-sectional area of the chamber with correspondingly lower emulsifying power. While the orifice of the barrier plate in my drawings is substantially circular, it is understood that various shapes such as square, rectangular or oval, may be employed with equal success in the practice of my invention. Preferably the orifice 25 of the barrier plate is located in the middle of the barrier plate, and preferably the barrier plate is located midway in the housing forming two equal sections.

The housing is provided with a conduit 7 for receiving the material to be emulsified, and an outlet conduit 8 for the emulsified material. The inlet conduit 7 is at the bottom of the first section, and preferably at the middle, and the outlet conduit 8 is at the top of the second section and preferably at the middle. The inlet and/or outlet can, of course, be reversed, but this is the most logical position for them. Preferably the diameter of the inlet and outlet conduits are approximately equal. The best results have been obtained when the diameter of the orifice 25 is of a size about equal to the size of the inlet conduit 7. While the inlet and outlet conduits are substantially circular, as shown, it is understood that various other shapes may be employed in the practice of my invention.

A packing and bearing structure 20 is located between the casing for the first section 1, the packing gland l2, and the removable closure plate 9, and has shaft 11 extending horizontally through it. The shaft 11 is supported and allowed to rotate by the packing and barrier structure 20. This packing and barrier structure also fonns an adequate seal with the shaft and the casing for the first section, the removable closure plate, and the packing gland.

The shaft 11 extends through the interior of the housing, passing through the packing and barrier structure 20, through the shaft opening 27 in the casing of the first section, through the first section, through the barrier plate preferably by means of the orifice 25, and into the second section. The shaft as shown in the drawings is in the horizontal plane. The shaft 11 can, of course, pass through the barrier plate by means of an opening provided in it other than the orifice 25, although it is preferred to have the shaft pass through the middle of it by means of orifice 25, and at right angles to the barrier plate. It is, of course, recognized that the diameter of the shaft must be smaller than the diameter of the orifice 25 in order that the material can pass from the first section to the second secu'on of the apparatus, when the shaft passes through orifice 25. This shaft 11 is adapted to be driven by an electric motor or the like (not illustrated). It is, of course, understood that instead of using a single shah extending through the housing, it is possible to provide each section with its own individual shaft and to adapt each shaft to be driven by a separate electric motor or the like.

Two rotary impellers, 21 and 23, are rigidly connected to shaft 11 by means of impeller hubs 22 and 30, respectively. Rotary impeller 21 is positioned in the first section, preferably in the middle, and rotary impeller 23 is positioned in the second section of the housing, preferably in the middle, and as shown are substantially vertical. As shown the impellers must be coaxial.

Each rotary impeller contains an arm 29, perforated plate 31 which is perpendicular to said arm, and which has holes 24 therein. Each rotary impeller can contain two sets of arms 29 as shown in FIG. 12.

The holes 24 in the impeller decrease the surface area and increase the shearing edge of the impellers. The general efieet is that produced by two liquids being forced through an orifice. This gives the apparatus an additional emulsifying process. While the holes as shown are substantially circular, it is understood that various other shapes may be employed in the practice of my invention. Also, instead of holes, the impellers can be notched to decrease their surface area and increase their shearing edge. It is, of course, recognized that it is not necessary to have a perforated or notched plate perpendicular to the arm of the impeller. Also, the arm of the impeller can be perforated or notched.

FIG. 12 illustrates a rotary impeller containing two sets of arms 29 and having plates which have notches 71 and which are perpendicular to said arms. Arms 29 are provided with holes 72.

The two impellers are in a spaced relationship with the interior of the housing, the barrier plate 2, and with each other. It is, of course, recognized that the impellers do not have to be spaced from the casing or barrier plate, when they are perforated or notched, since the material will flow through the holes or orifices in the arm. It is, however, preferred to have the impellers in a spaced relationship with the casing and barrier plate, since it is much easier and less expensive to prepare the apparatus this way. When not in a spaced relationship, considerable accuracy and close tolerances in manufacture are necessary, which would increase the cost of the equipment considerably. The space between the interior walls of the easing, the barrier plate, and the impellers is designated by 26.

The periphery of the first impeller 21 is located opposite the material inlet conduit 7, with the inlet conduit tending to introduce material in the direction of rotation of the impellers. The periphery of the second or last rotary impell 23 is located opposite the material outlet conduit 8. Also, the best results have been obtained when the first and second impellers are positioned such that the barrier plate 2 is midway between them.

Instead of only two rotary impellers, is contemplated to employ three or more coaxial rotary impellers. There will be a vertically positioned barrier plate located between each adjacent set of rotary impellers similar to the barrier plate 2 discussed above. FIGS. 7, 8 and show an apparatus containing three coaxial rotary impellers.

Referring to FIGS. 4-11, I have shown a housing which consists of a casing for a first section 1, barrier plate 2, a casing for a second section 41, barrier plate 40, and a casing for a last section 3, all being connected together by fasteners 5 and 6 (e.g., nuts and bolts), a plug 4, a packing gland 12, a removable closure plate 9 being connected to the packing gland by fasteners 10 (e.g., bolts). The casing for the first section has a shaft opening 27, preferably in the middle. The casing for the second section has a breather hole 74 to prevent vapor locking.

The circular interior of the housing is divided into three sections by barrier plates 2 and 40 vertically positioned and each having a diameter at least equal to the diameter of the interior of the housing. The barrier plates 2 and 40 each have an orifree 25 which allows the material being emulsified to pass from one side to the other side of each plate.

The previous discussion with respect to the size, position and shape of the orifice 25 likewise applies to each orifice 25 in barrier plates 2 and 40 in the three section apparatus. Preferably the barrier plates 2 and 40 are located in the housing so as to form three equal sections.

The housing is provided with a conduit 7 for receiving the material to be emulsified, and an outlet conduit 8 for the emulsified material. The inlet conduit 7 is at the bottom of the first section, and preferably at the middle and the outlet conduit 8 is at the top of the last section and preferably at the middle. The inlet and/or outlet can, of course, be reversed but this is the most logical position for them. Preferably the diameter of the inlet and outlet conduits are approximately equal. The best results have been obtained wherein the diameter of each orifice 25 is of a size about equal to the size of the inlet conduit 7. While the inlet and outlet conduits are substantially circular, as shown, it is understood that various other shapes may be employed in the practice of my invention.

A packing and bearing structure 20 is located between the casing for the first section 1, the packing gland l2, and the removable closure plate 9, and has shaft 42 extending horizontally through it. The shaft 42 is supported and allowed to rotate by the packing and barrier structure 20. This packing and barrier structure also forms an adequate seal with the shaft and the casing for the first section, the removable closure plate, and the packing gland.

The shaft 42 extends through the interior of the housing, passing through the packing and barrier structure 20, through the shaft opening 27 in the casing of the first section, through the first section, through the barrier plate 2 preferably by means of the orifice 25, through the second section, through the barrier plate 40 preferably by means of the orifice 25, and into the third section. The shaft 42 as shown in the drawings is in the horizontal plane. The previous discussion with respect to shaft 11 in the two zone apparatus likewise applies to the shaft 42. Also, shaft 42 is adapted to be driven by an electric motor or the like (not illustrated). It is, of course, understood that instead of using a single shaft extending through the housing, it is possible to provide each section with its own individual shaft and to adapt each shaft to be driven by separate electric motor or the like.

Three rotary impellers, 43 and 23 are rigidly connected to shaft 42 by means of impeller hubs 22, 44 and 30, respectively. Rotary impeller 21 is positioned in the first section, preferably in the middle. Rotary impeller 34 is positioned in the second section, preferably in the middle, and rotary impeller 23 is positioned in the third section of the housing, preferably in the middle. As shown, all of the impellers are substantially vertical. As shown the impellers must be coaxial.

The previous discussion concerning the design and positioning of the rotary impellers likewise applies to the three rotary impellers in the three section apparatus.

Also in any or all of the intermediate stages, a rotary impeller of the type shown FIG. 14 can be used in place of the above described rotary impellers. This type of rotary impeller contains a solid disc 62, perforated plates 69 which are perpendicular to said disc, and which have holes 24 therein. It is, of course, recognized that instead of holes, the plates can be notched.

The periphery of the first impeller 21 is located opposite the material inlet conduit 7, with the inlet conduit tending to introduce material in the direction of rotation of the impellers. The periphery of the last rotary impeller 23 is located opposite the material outlet conduit 8. Also, the best results have been obtained when the impellers are positioned such that the barrier plate 2 is midway between impellers 21 and 43 and barrier plate 40 is midway between impellers 43 and 23.

Referring to FIGS. 13 and 14, I have shown a housing which consists of a casing 63, a packing gland 12, a removable closure plate 9 being connected to the packing gland by fasteners 10 (e.g., bolts). The casing for the apparatus has an opening 65 for the shaft and for the material. The interior of the housing is separated into two zones by barrier means 62 vertically positioned and having an orifice 66 which allows the shaft to pass through it. In addition, the barrier means is provided with means for allowing the material to pass from the periphery of the first impeller through the barrier means to the periphery of the second impeller. This means as shown in FIG. 13 is the clearance 64 between the interior 73 of the casing 63 and the barrier means 62.

The barrier means 62 shown in drawings 13 and 14 is the solid disc 62 of the rotary impeller. This being the preferred barrier means because of ease of construction and other economic factors. It is, of course, understood that other barrier means can be employed, as long as the means only permits material to flow from the periphery of the first rotary impeller to the periphery of the second rotary impeller.

For best results the means 64 for allowing material to pass from one zone to the other zone should have a diameter about equal to the width 70 of the rotary impeller 67. The diameter of the clearance 64 can, of course, be somewhat smaller than the width 70 of the rotary impeller but this may cause a back pressure in the apparatus. Also, the clearance 64 may be larger with corresponding lower emulsifying power.

The housing is provided with a conduit 60 for receiving the material to be emulsified and an outlet 61 for the emulsified material. The inlet 60 is at the top of the first section and preferably at the middle and the outlet 61 is at the center of the second zone.

A packing and barrier structure 20 is located between the casing for the first section 1, the packing gland 12, and the removable closure plate 9, and has a shaft extending horizontally through it. The shaft 1 l is supported and allowed to rotate by the packing and barrier structure 20.

The shaft 11 passes through the interior of the housing, passing through the packing and barrier structure 20, through the shaft openings 65 in the casing of the housing, through the first zone, through the barrier means of an orifice 66 and into the second zone. The shaft, as shown in the drawings, is in a horizontal plane. It is, of course, recognized that the orifice 66 can be positioned other than in the middle of the barrier means, although it is preferred to have the shaft pass through the middle of the barrier means 62, and at right angles to it. It is, of course, recognized that the diameter of the shaft and the diameter of the orifice 66 must form substantially leak-proof fit to prevent material from passing through the barrier means at this point; thereby avoiding the emulsifying action of the apparatus.

Of course, it is recognized that instead of using single shaft extending through the housing, it is possible to provide each zone with its own individual shaft and to adopt each shaft to be driven by a separate electrical motor or the like.

Two rotary impellers 21 and 67 are rigidly connected to the shaft 11 by means of impeller hubs 22 and 68, respectively. Rotary impeller 67 is positioned in the second zone of the housing, preferably in the middle, and as shown is substantially vertical. As shown, the impellers must be coaxial. Impeller 67 contains a solid disc 62, perforated plate 69, which have holes 24 therein.

The hub of the first impeller 21 is located at the material inlet 60, with the inlet conduit tending to introduce material in the direction of rotation of the impellers. The material outlet is located at the hub of the second or last rotary impeller 67. The best results are obtainable when the first and second impellers are positioned such that the barrier means is midway between them.

Instead of only two rotary impellers for this apparatus, it is contemplated to employ additional stages. Such can be done merely by having outlet 6] feed into the inlet of another twozone apparatus of the type set forth in FIGS. 13 and 14 at the hub of the first rotary impeller of the additional apparatus.

In the performance of my invention, when using the ap paratus shown in FIGS. 1-6, a continuous stream of materials to be emulsified, such as a mixture of water, styrene, catalyst, accelerator and polyester, is forced by gravity or an auxiliary pump (not shown) into the material inlet 7 located at the bottom of the casing for the first section and opposite the periphery of the first rotary impeller. Both the first and second impellers will operate one against the other at the intake end tending to pump material outwardly, but since this is not possible, there would be no substantial liquid flow without the gravity or auxiliary pump mentioned above. The first impeller tends to pump material outward towards inlet 7, whereas; the second impeller tends to pump material outward towards outlet 8. The impellers tend to neutralize the pumping action of each other with the development of a small confined area where extremely high shear and extremely high turbulence is obtained which is capable of emulsifying the liquids at a very rapid rate. When the external driving force (gravity or auxiliary pump) is sufficiently large to keep the unit substantially full (preferably completely full), emulsified material will be forced from the periphery of the first impeller to the interior wall of the barrier plate, through the orifice of the barrier plate into the second section, to the periphery of the second rotary impeller, and out through the outlet conduit by the introduction through the inlet conduit of additional material.

When more than two rotary impellers are employed, such as with the three impellers as shown in FIGS. 7 to 11, the material is forced by gravity or an auxiliary pump (not shown) into the material inlet 7, located at the bottom of the casing for the first section and opposite the periphery of the first rotary impeller. The material will then be forced from the periphery of the first impeller to the interior wall of the barrier means, through the orifice of the barrier means into the second section, through the second section, through the orifice of the second barrier plate into a third zone, to the periphery of the third rotary impeller and out through the outlet conduit. The driving force of the second and third impellers tend to pull material in the same direction as each other, but tend to pull material in a direction opposite the driving force of the first impeller.

When more than two rotary impellers are employed, such as with the three rotary impellers, and the second rotary impeller is of the solid disc type as shown in FIG. 14, the material after being forced through the orifice of the barrier plate into the second rotary impeller, forced to the periphery of the second rotary impeller, forced to the interior wall of the second barrier plate, through the orifice of the second barrier plate into a third zone, to the periphery of the third rotary impeller, and out through the outlet conduit. The driving force of the second and third impeller tends to pull material in the same direction as each other, while tending to pull material in the opposite direction from the driving force of the first impeller.

In the performance of my invention, when using the apparatus as shown in FIGS. 13 and 14, a continuous stream of materials to be emulsified, such as a mixture of water, styrene, catalysts, accelerator, and polyester, is forced by gravity or an auxiliary pump (not shown) into the material inlet 60, located at the top of the casing for the first section and at the hub of the first rotary impeller. Both the first and second impellers will operate one against the other at the inlet end tending to pump outwardly, but since this is not possible, there will be no substantial liquid flow without the gravity of auxiliary pump mentioned above.

The impellers tend to neutralize the pumping action of each other with the development of a small confined area where extremely high shear and extremely high turbulence is obtained which is capable of emulsifying the liquids at a very rapid rate. When the external driving force (gravity or auxiliary pump) is sufficiently large to keep the unit substantially full (preferably completely full), material will be forced from the periphery of the first impeller through the barrier means to the periphery of the second rotary impeller, through the second section and out through the outlet conduit at the hub of the second impeller by the introduction through the inlet conduit of additional material.

Of course, if desired, additional stages can be employed.

The advantage of having more than two rotary impellers is that the material is subjected to the action of the impellers for a longer time, thereby adequately insuring complete emulsification of materials extremely difficult to emulsify. Of course, the advantages of having additional impellers must be weighed against the increased costs of the apparatus to determine if such cost is warranted for a particular use of the apparatus.

I have been able to feed a mixture of water, styrene, catalyst, accelerator and polyester, into my apparatus, and am able to produce very homogeneous inverse polymeric emulsions (water-in-oil emulsions) with a throughput in relative volume units per second of 35 times the holdup capacity of the unit. This is a particularly valuable advantage when working with resins catalyzed to cure within minutes of emulsification, since the danger of gellation in the mixer is sharply reduced.

It is, of course, understood that the particular catalyst-accelerator system and polyester to be used are not a part of the present invention, and need not be described in any greater detail. Numerous catalyst-accelerator systems for inverse polyester emulsions are currently in commercial use and are described in the patent literature. For example, see U.S. Pat. Nos. 3,256,219 and 3,244,772.

The apparatus exhibits unexpected results as compared to using a single centrifugal pump as designed since when using such an apparatus the inlet tended to leak air and produced only a very foamy emulsion. Also, I found that such a pump was limited in its capacity and the amount of water that could be incorporated into the emulsion. When using a single centrifugal pump while purposely generating back-pressure against the pump with a restriction or other means downstream thereof, it was found that the liquid metering units were adversely affected, and therefore such use of a centrifugal pump could not conveniently be employed as an inline blender in an emulsification process.

Unlike conventional centrifugal pumps wherein a vacuum is created at the inlet, and a pressure at the outlet, the pressure at the inlet and outlet of my apparatus are substantially the same.

The process of my invention produced homogeneous emulsions by subjecting flowable materials to the action of very high shear and very high turbulence by the various steps which will be discussed below.

The first step of one process aspect of my invention is the forcing (e.g., by pumping) of at least two flowable materials into a first zone wherein a centrifugal force is present. The material must be forced into the first zone in a direction opposing the direction of the driving force of the centrifugal force. The term direction of the driving force of the centrifugal force and similar terms as used herein refers to the radially outwardly directed centrifugal force. The material is then removed from the first zone and forced into a second zone, wherein another centrifugal force is present. Preferably the size of the second zone is about equal to the size of the first zone. Preferably, the second zone is directly adjacent the first zone, although this is not necessary so long' as the added pressure drop which might occur in any pipe connecting the separated zones can be tolerated. The material passage zone between the two zones is subject to the same size limitations discussed in connection with the orifice 25. The force in the second zone must tend to pull material in the opposite direction from the force in the first zone. Preferably, the centrifugal force in the second zone is about equal in magnitude to and coaxial with the force in the first zone. The material must be forced into this second zone in a direction cooperating with the direction of the driving force of the centrifugal force.

After the materials have been subjected to the forces in the f'ust and second zones, they are in the form of a homogeneous emulsion, and are removed from the second section. Preferably, the emulsion is removed from the top of the second zone at the middle.

The above process can be performed employing the apparatus as shown in FIGS. 1-6.

As previously indicated, it is contemplated to provide more than two zones, such as, for example, three zones. In such a process, after the materials have been subjected to the forces in the first and second zones, they are forced into the third zone wherein another centrifugal force is present. Preferably, the size of the third zone is about equal to the size of the second zone. Preferably, the third zone is directly adjacent the second zone, although this is not necessary so long as the added pressure drop which might occur in any pipe connecting the separated zones can be tolerated. The material passage zone between adjacent zones is subject to the same size limitations discussed in connection with the orifice 25. The force in the third zone tends to pull material in the same direction as the force in the second zone. Preferably, the centrifugal force in the third zone is about equal in magnitude to and coaxial with the force in the second zone. The material must be forced into this third zone in a direction cooperating with the direction of the driving force of the centrifugal force.

After the materials have been subjected to the forces in the three zones, they are in the form of a homogeneous emulsion, and are removed from the third section. Preferably, the emulsion is removed from the top of the third zone at the middle.

The first step of the other process aspect of my invention is of forcing (e.g., by pumping) of at least two flowable materials into a first zone wherein a centrifugal force is present. The material is forced into the first zone in a direction cooperating with the direction of the driving force of the centrifugal force. The material is then removed from the first zone and forced into a second zone wherein another centrifugal force is present. Preferably, the size of the second zone is about equal to the size of the first zone. Preferably, the second zone is exactly adjacent the first zone, although this is not necessary so long as the added pressure drop which might occur in any pipe connecting the separated zones can be tolerated. The material passage zone between the two zones is subject to the same size limitations discussed in connection with the means 25. The force in the second zone must tend to pull material in the opposite direction from the force in the first zone. Preferably, the centrifugal force in the second zone is about equal in magnitude to and coaxial with the force in the first zone. The material must be forced into the second zone in a direction opposing the direction of the driving force of the centrifugal force. After the materials have been subjected to the force in the first and second zones, they are in the form of a homogeneous emulsion and are removed from the second zone. This process can be performed employing the apparatus as shown in FIGS. 13 and 14.

The materials which may be emulsified using my novel process are not limited to the water, styrene and polyester shown, but include numerous other materials which are flowable and emulsifiable. Any types of emulsions of oils, asphalts, waxes, pigments, soaps, fibers such as asbestos, rubbers (natural and synthetic), natural resins, and synthetic polymers such as polyolefins, polyepoxides, polysiloxanes, polyamides, styrene polymers, polyirnides, phenolic resins, acrylate polymers, vinyl chloride polymers and polyesters are nonlirniting examples of various emulsions contemplated to be prepared by my novel process.

What is claimed is:

l. A process for preparing a homogeneous emulsion by subjecting at least two flowable materials to the action of high shear and high turbulence comprising a. forcing at least two flowable materials into a first zone wherein is present a centrifugal force;

b. removing said materials from the first zone;

c. forcing said materials into at least one additional zone wherein is present a centrifugal force;

d. the materials are forced through one of said zones against the radially outwardly directed centrifugal force therein and the materials are forced through the other zone in cooperation with the radially outwardly directed centrifugal force in the other zone;

e. the centrifugal forces in said first zone and said at least one additional zone tending to pull material in opposite directions; and

f. removing a homogeneous emulsion of the material from said at least one additional zone.

2. The process of claim 1 wherein the flowable materials are forced through the first zone against the radially outwardly directed centrifugal force present in the first zone; and wherein the materials are forced through the at least one additional zone in cooperation with the radially outwardly directed centrifugal force present in said at least one additional zone.

3. The process of claim 1 wherein the at least one additional zone comprises a second zone and a third zone, and wherein materials are forced through the second zone in cooperation with the radially outwardly directed centrifugal force present in said second zone, said materials are removed from the second zone, said materials are forced through the third zone in cooperation with the radially outwardly directed centrifugal force present in said third zone, and the centrifugal force in said first zone tending to pull material in the opposite direction from the centrifugal forces in said second and third zones.

4. The process of claim 3 wherein said first and second zones are directly adjacent each other, and have a common material passage zone, and wherein said second and third zones are directly adjacent each other and have a common material passage zone.

5. The process of claim 1 wherein said forces in said first and said at least one additional zone are coaxial.

6. The process of claim 1 wherein said zones are of substantially equal size.

7. The process of claim 1 wherein the materials are forced vertically upward into said first zone.

8. The process of claim 1 wherein said forces in said zones are of substantially equal magnitude.

9. The process of claim 1 wherein said at least one addition zone comprises a second zone, and said materials are forced through a second zone in cooperation with the radially outward directed centrifugal force present in said second zone, and the centrifugal force in said first zone tending to pull material in the opposite direction from the centrifugal force in said second zone.

10. The process of claim 9 wherein said first and second zones are directly adjacent each other and have a common material passage zone. 

2. The process of claim 1 wherein the flowable materials are forced through the first zone against the radially outwardly directed centrifugal force present in the first zone; and wherein the materials are forced through the at least one additional zone in cooperation with the radially outwardly directed centrifugal force present in said at least one additional zone.
 3. The process of claim 1 wherein the at least one additional zone comprises a second zone and a third zone, and wherein materials are forced through the second zone in cooperation with the radially outwardly directed centrifugal force present in said second zone, said materials are removed from the second zone, said materials are forced through the third zone in cooperation with the radially ouTwardly directed centrifugal force present in said third zone, and the centrifugal force in said first zone tending to pull material in the opposite direction from the centrifugal forces in said second and third zones.
 4. The process of claim 3 wherein said first and second zones are directly adjacent each other, and have a common material passage zone, and wherein said second and third zones are directly adjacent each other and have a common material passage zone.
 5. The process of claim 1 wherein said forces in said first and said at least one additional zone are coaxial.
 6. The process of claim 1 wherein said zones are of substantially equal size.
 7. The process of claim 1 wherein the materials are forced vertically upward into said first zone.
 8. The process of claim 1 wherein said forces in said zones are of substantially equal magnitude.
 9. The process of claim 1 wherein said at least one addition zone comprises a second zone, and said materials are forced through a second zone in cooperation with the radially outward directed centrifugal force present in said second zone, and the centrifugal force in said first zone tending to pull material in the opposite direction from the centrifugal force in said second zone.
 10. The process of claim 9 wherein said first and second zones are directly adjacent each other and have a common material passage zone. 